# Factory-built Chimney: Building Code Definition

> How the IRC 2009 define factory-built chimney, where the wording differs, and which chapters depend on the term.

- Canonical: https://harth.build/resources/glossary/factory-built-chimney/
- Last updated: 2026-09-07
- Data source: Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The [ICC code library](https://codes.iccsafe.org/codes) publishes the current model text and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) show which edition a jurisdiction has adopted; those sources control.

## Key facts

| Fact | Value |
| --- | --- |
| Defined in | IRC 2009 (2009 editions transcribed in this corpus) |
| Primary source | IRC 2009 Definitions (model text, not a jurisdiction's adopted text) |
| Chapters using the term | 9 (counted across the codes hosted here) |
| Wording identical across codes | Single code (compare before citing one code's wording under another) |

## Direct answer

Factory-built chimney is a defined term in the International Residential Code (IRC) 2009, in Definitions. The code's own words are: “A listed and labeled chimney composed of factory-made components assembled in the field in accordance with the manufacturer's instructions and the conditions of the listing.” No other I-Code in this corpus defines it, so the IRC 2009 definition is the one to work from. The term is used in 9 chapters of this corpus, most often in Fuel Gas (IRC 2009), Chimneys and Vents (IMC 2009), Chimneys and Fireplaces (IRC 2009). These pages transcribe the 2009 model text; verify the definition against the edition and amendments your authority having jurisdiction has adopted. Record the jurisdiction, the adopted edition, the application date and any local amendment that rewrites the definition before you use it on a live project, because a term redefined by amendment changes every requirement that depends on it.

*Content and cited inputs reviewed by [Scott Barrington](https://nz.linkedin.com/in/barrington), Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.*

## What does this term mean?

**Factory-built Chimney** — IRC 2009, Definitions:

> A listed and labeled chimney composed of factory-made components assembled in the field in accordance with the manufacturer's instructions and the conditions of the listing.

![Labeled code-term definition diagram: Factory-built Chimney: Building Code Definition](https://efwwel0vyt9vy5so.public.blob.vercel-storage.com/images/glossary/factory-built-chimney/diagram-1344.webp)

*How the IRC 2009 define factory-built chimney, where the wording differs, and which chapters depend on the term.*

## What must be verified before using this guidance?

**Factory-built Chimney** is defined once in this corpus, in the [Definitions](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/definitions.md) chapter of the International Residential Code (IRC) 2009:

> A listed and labeled chimney composed of factory-made components assembled in the field in accordance with the manufacturer's instructions and the conditions of the listing.

## Where factory-built chimney is used in the code

The term appears in 9 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

| Chapter | Code | Mentions |
| --- | --- | --- |
| [Fuel Gas](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/fuel-gas.md) | IRC 2009 | 29 |
| [Chimneys and Vents](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/chimneys-and-vents.md) | IMC 2009 | 14 |
| [Chimneys and Fireplaces](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/chimneys-and-fireplaces.md) | IRC 2009 | 10 |
| [Building Services and Systems](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/building-services-and-systems.md) | IFC 2009 | 9 |
| [Fire and Smoke Protection Features](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/fire-and-smoke-protection-features.md) | IBC 2009 | 6 |
| [Chimneys and Vents](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/chimneys-and-vents.md) | IRC 2009 | 3 |
| [Masonry](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/masonry.md) | IBC 2009 | 2 |
| [Definitions](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/definitions.md) | IMC 2009 | 2 |
| [Definitions](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/definitions.md) | IRC 2009 | 1 |

### The term in use

How the code actually writes about factory-built chimney, quoted from the 2009 text hosted here:

> Chimneys shall extend at least 5 feet (1524 mm) above the highest connected appliance drafthood outlet or flue collar: Decorative shrouds shall not be installed at the termination of factory-built chimneys except where such shrouds are listed and labeled for use with the specific factory-built chimney system and are installed in accordance with the manufacturer's installation instructions.

— [IRC 2009 §G2427.5.3](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/fuel-gas.md)

> Every fuel-burning appliance shall discharge the products of combustion to a vent, factory-built chimney or masonry chimney, except for appliances vented in accordance with Section 804.

— [IMC 2009 §801.2](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/chimneys-and-vents.md)

> Decorative shrouds shall not be installed at the termination of factory-built chimneys except where the shrouds are listed and labeled for use with the specific factory-built chimney system and installed in accordance with the manufacturer's installation instructions.

— [IRC 2009 §RI005.2](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/chimneys-and-fireplaces.md)


## The terms factory-built chimney is built out of

The definition above leans on 3 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what factory-built chimney covers:

- **[Labeled](https://harth.build/resources/glossary/labeled.md)** — IBC 2009: Equipment, materials or products to which has been affixed a label, seal, symbol or other identifying mark of a nationally recognized testing laboratory, inspection agency or other organization concerned with product evaluation that maintains periodic inspection of the production of …
- **[Chimney](https://harth.build/resources/glossary/chimney.md)** — IBC 2009: A primarily vertical enclosure containing one or more passageways for conveying flue gases to the outside atmosphere.
- **[Listed](https://harth.build/resources/glossary/listed.md)** — IBC 2009: Equipment, materials, products or services included in a list published by an organization acceptable to the code official and concerned with evaluation of products or services that maintains periodic inspection of production of listed equipment or materials or periodic evaluation …

## Factory-built Chimney: what to open, and in what order

Every row is a document this term depends on. The [ICC code library](https://codes.iccsafe.org/codes) and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) cover the middle rows.

| Check | Where | Confirmed |
| --- | --- | --- |
| Read the definition in the adopted IRC | Definitions | |
| Re-check the requirement that uses it | Fuel Gas (IRC 2009) | |
| Re-check the requirement that uses it | Chimneys and Vents (IMC 2009) | |
| Re-check the requirement that uses it | Chimneys and Fireplaces (IRC 2009) | |
| Re-check the requirement that uses it | Building Services and Systems (IFC 2009) | |
| Confirm the dependent definition | Labeled | |
| Confirm the dependent definition | Chimney | |
| Confirm the dependent definition | Listed | |
| Local amendment to any of the above | Jurisdiction's amendment list | |

**A research aid, not a code determination.** The authority having jurisdiction decides which edition and which amendments apply.

## Where can you explore related guidance?

- [Explore all glossary guidance](https://harth.build/resources/glossary.md)
- [Labeled: Building Code Definition](https://harth.build/resources/glossary/labeled.md)
- [Chimney: Building Code Definition](https://harth.build/resources/glossary/chimney.md)
- [Listed: Building Code Definition](https://harth.build/resources/glossary/listed.md)

## Sources and method

Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The [ICC code library](https://codes.iccsafe.org/codes) publishes the current model text and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) show which edition a jurisdiction has adopted; those sources control.

### Source links

- [codes.iccsafe.org](https://codes.iccsafe.org/codes)

- [iccsafe.org](https://www.iccsafe.org/advocacy/code-adoption-maps/)

## Frequently asked questions

### What is the code definition of factory-built chimney?

The International Residential Code (IRC) 2009 defines it in Definitions as: “A listed and labeled chimney composed of factory-made components assembled in the field in accordance with the manufacturer's instructions and the conditions of the listing.” The 2009 model text is reproduced here; the definition that binds your project is the one in the edition your jurisdiction has adopted, as amended locally.

### Which parts of the code depend on factory-built chimney?

In this corpus the term is used across 9 chapters, led by Fuel Gas in the IRC 2009. Those are the sections whose scope moves if the definition is amended locally, so read them together with Chapter 2 rather than on their own.

### What does a factory-built fireplace look like?

Fireplace is a separate defined term. The IBC 2009 defines it as: “A hearth and fire chamber or similar prepared place in which a fire may be made and which is built in conjunction with a chimney.” That is not the same as factory-built chimney, which the IRC 2009 defines as “A listed and labeled chimney composed of factory-made components assembled in the field in accordance with the manufacturer's instructions and the conditions of the listing.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.

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